My upload dies before it finishes.
A slow or unreliable Internet connection can further limit the size of the video you can upload. Try uploading at a different time of day or from a computer with a faster internet connection. Keep trying (don’t worry, failed attempts don’t count against your storage space limit). http://en.support.wordpress.com/videopress/#frequently-asked-questions

How you are connecting to the internet and to WordPress.com?
The way you connect to the internet (mobile, satellite, DSL, dial-up) and to your blog, and how many proxy server jumps etc. it takes to connect can cause problems. There maybe be problems with your ISP and/or with the proxy servers. Also note that the main dashboard isn’t designed to work with touch devices through the tablet and smartphone browsers.

(1) I had the customization upgrade, and almost instantly it turned out that half of the customization options for the theme I had were not available.

(2) Today, I got Videopress, and the 3 videos I uploaded early this evening are still "processing", after a message appeared "ready in 5 minutes". I am in the midst of a DAILY video-podcast, and this "upgrade" is in the way.

My videos take less than 5 minutes to upload AND process elsewhere FREE (youtube, blip.tv, and several distribution sites).

How can I publish a daily video-podcast, if each video takes 3 days to process?

From a business standpoint, I just don't get what wordpress.com is doing, if with the paid "upgrades" one actually pays for problems one did not have before 2 times out of 2(!).